Water → Quinoline-3-boronic acid

A solution of 3-bromoquinoline (14.6 g (0.07 mole)) in 50 ml of diethylether was added at -40° under argon to a solution of 2 M n-BuLi (37.5 ml (0.075 mole) (in cyclohexane)) in 50 ml Et2O. The reaction mixture was stirred 15 minutes and 0.075 mole (7.8 g, 8.5 ml) trimethylborate was added rapidly over 2 minutes. The mixture was stirred 15 minutes at 0° C. and 4 ml of H2O was added and stirring continued for 30 minutes. The volatiles were evaporated in vacuo to a yellow tar resi-due. The residue was dissolved in 150 ml ethyl alcohol to which was added 4 ml of acetic acid and reflux-ed for 45 minutes. The volatiles were evaporated in vacuo to a yellow oily residue. The residue was stirred with 40 ml of ether to give a yellow solid which was filtered, washed with ether and dried to give 11.14 g of a solid. The solid was stirred in 100 ml of water and filtered to give 3.26 g of a solid after air drying. The crude product was used directly in the next step.

1. stirringThe mixture was stirred 15 minutes at 0° C.
2. stirringstirring
3. waitcontinued for 30 minutes
4. customThe volatiles were evaporated in vacuo to a yellow tar resi-due
5. dissolutionThe residue was dissolved in 150 ml ethyl alcohol to which
6. additionwas added 4 ml of acetic acid
7. temperaturereflux-ed for 45 minutes
8. customThe volatiles were evaporated in vacuo to a yellow oily residue
9. stirringThe residue was stirred with 40 ml of ether
10. customto give a yellow solid which
11. filtrationwas filtered
12. washwashed with ether
13. customdried

ORD record

ord-1469785fc6894cc1882387a60699fc68

Source dataset

uspto-grants-1999_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05908840